Remove Emit entry in favor of auto-emitting code

All instructions but OpVariable and OpLabel are automatically emitted.
These functions have to call AddLocalVariable/AddGlobalVariable or
AddLabel respectively.

include/sirit/sirit.h

@@ -70,12 +70,26 @@ public:
     }
 
     /**
-     * Adds an instruction to module's code
-     * @param op Instruction to insert into code. Types and constants must not
-     * be emitted.
-     * @return Returns op.
+     * Adds an existing label to the code
+     * @param label Label to insert into code.
+     * @return Returns label.
      */
-    Id Emit(Id op);
+    Id AddLabel(Id label);
+
+    /**
+     * Adds a label to the code
+     * @return Returns the created label.
+     */
+    Id AddLabel() {
+        return AddLabel(OpLabel());
+    }
+
+    /**
+     * Adds a local variable to the code
+     * @param variable Variable to insert into code.
+     * @return Returns variable.
+     */
+    Id AddLocalVariable(Id label);
 
     /**
      * Adds a global variable

src/instructions/flow.cpp

@@ -30,7 +30,7 @@ Id Module::OpSelectionMerge(Id merge_block, spv::SelectionControlMask selection_
 }
 
 Id Module::OpLabel() {
-    return AddCode(spv::Op::OpLabel, bound++);
+    return code_store.emplace_back(std::make_unique<Op>(spv::Op::OpLabel, bound++)).get();
 }
 
 Id Module::OpBranch(Id target_label) {

src/instructions/memory.cpp

@@ -16,7 +16,7 @@ Id Module::OpVariable(Id result_type, spv::StorageClass storage_class, Id initia
     if (initializer) {
         op->Add(initializer);
     }
-    return AddCode(std::move(op));
+    return code_store.emplace_back(std::move(op)).get();
 }
 
 Id Module::OpLoad(Id result_type, Id pointer, std::optional<spv::MemoryAccessMask> memory_access) {

src/sirit.cpp

@@ -98,22 +98,24 @@ void Module::AddExecutionMode(Id entry_point, spv::ExecutionMode mode,
     execution_modes.push_back(std::move(op));
 }
 
-Id Module::Emit(Id op) {
-    assert(op != nullptr);
-    code.push_back(op);
-    return op;
+Id Module::AddLabel(Id label) {
+    assert(label != nullptr);
+    return code.emplace_back(label);
+}
+
+Id Module::AddLocalVariable(Id variable) {
+    assert(variable != nullptr);
+    return code.emplace_back(variable);
 }
 
 Id Module::AddGlobalVariable(Id variable) {
     assert(variable);
-    global_variables.push_back(variable);
-    return variable;
+    return global_variables.emplace_back(variable);
 }
 
 Id Module::AddCode(std::unique_ptr<Op> op) {
-    const auto id = op.get();
-    code_store.push_back(std::move(op));
-    return id;
+    const Id id = code_store.emplace_back(std::move(op)).get();
+    return code.emplace_back(id);
 }
 
 Id Module::AddCode(spv::Op opcode, std::optional<u32> id) {

tests/main.cpp

@@ -46,30 +46,30 @@ public:
         AddGlobalVariable(in_pos);
         AddGlobalVariable(per_vertex);
 
-        const auto main_func = Emit(
+        const auto main_func = 
             Name(OpFunction(t_void, spv::FunctionControlMask::MaskNone, TypeFunction(t_void)),
-                 "main"));
-        Emit(OpLabel());
+                 "main");
+        AddLabel();
 
-        const auto ptr_pos_x = Emit(OpAccessChain(in_float, in_pos, Constant(t_uint, 0u)));
-        const auto ptr_pos_y = Emit(OpAccessChain(in_float, in_pos, Constant(t_uint, 1u)));
+        const auto ptr_pos_x = OpAccessChain(in_float, in_pos, Constant(t_uint, 0u));
+        const auto ptr_pos_y = OpAccessChain(in_float, in_pos, Constant(t_uint, 1u));
 
-        const auto pos_x = Emit(OpLoad(t_float, ptr_pos_x));
-        const auto pos_y = Emit(OpLoad(t_float, ptr_pos_y));
+        const auto pos_x = OpLoad(t_float, ptr_pos_x);
+        const auto pos_y = OpLoad(t_float, ptr_pos_y);
 
-        auto tmp_position = Emit(OpUndef(float4));
+        auto tmp_position = OpUndef(float4);
         Decorate(tmp_position, spv::Decoration::FPRoundingMode,
                  static_cast<u32>(spv::FPRoundingMode::RTE));
-        tmp_position = Emit(OpCompositeInsert(float4, pos_x, tmp_position, 0));
-        tmp_position = Emit(OpCompositeInsert(float4, pos_y, tmp_position, 1));
-        tmp_position = Emit(OpCompositeInsert(float4, Constant(t_float, 0.f), tmp_position, 2));
-        tmp_position = Emit(OpCompositeInsert(float4, Constant(t_float, 1.f), tmp_position, 3));
+        tmp_position = OpCompositeInsert(float4, pos_x, tmp_position, 0);
+        tmp_position = OpCompositeInsert(float4, pos_y, tmp_position, 1);
+        tmp_position = OpCompositeInsert(float4, Constant(t_float, 0.f), tmp_position, 2);
+        tmp_position = OpCompositeInsert(float4, Constant(t_float, 1.f), tmp_position, 3);
 
-        const auto gl_position = Emit(OpAccessChain(out_float4, per_vertex, Constant(t_uint, 0u)));
-        Emit(OpStore(gl_position, tmp_position));
+        const auto gl_position = OpAccessChain(out_float4, per_vertex, Constant(t_uint, 0u));
+        OpStore(gl_position, tmp_position);
 
-        Emit(OpReturn());
-        Emit(OpFunctionEnd());
+        OpReturn();
+        OpFunctionEnd();
 
         AddEntryPoint(spv::ExecutionModel::Vertex, main_func, "main", in_pos, per_vertex);
     }